[PATCH 02/11] mm: swap: fix vmstats for huge pages

From: Shakeel Butt shakeelb@google.com

mainline inclusion from mainline-v5.8-rc1 commit 5d91f31faf8ebed2acfc3a1d6ac344f95c488d66 category: bugfix bugzilla: 36232 CVE: NA

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Many of the callbacks called by pagevec_lru_move_fn() does not correctly update the vmstats for huge pages. Fix that. Also __pagevec_lru_add_fn() use the irq-unsafe alternative to update the stat as the irqs are already disabled.

Signed-off-by: Shakeel Butt shakeelb@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Acked-by: Johannes Weiner hannes@cmpxchg.org Link: http://lkml.kernel.org/r/20200527182916.249910-1-shakeelb@google.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Liu Shixin liushixin2@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- mm/swap.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c index 320ac35bde26..a819f8746ee2 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -224,7 +224,7 @@ static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec, del_page_from_lru_list(page, lruvec, page_lru(page)); ClearPageActive(page); add_page_to_lru_list_tail(page, lruvec, page_lru(page)); - (*pgmoved)++; + (*pgmoved) += hpage_nr_pages(page); } }

@@ -284,7 +284,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec, add_page_to_lru_list(page, lruvec, lru); trace_mm_lru_activate(page);

- __count_vm_event(PGACTIVATE); + __count_vm_events(PGACTIVATE, hpage_nr_pages(page)); update_page_reclaim_stat(lruvec, file, 1); } } @@ -499,6 +499,7 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec, { int lru, file; bool active; + int nr_pages = hpage_nr_pages(page);

if (!PageLRU(page)) return; @@ -532,11 +533,11 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec, * We moves tha page into tail of inactive. */ list_move_tail(&page->lru, &lruvec->lists[lru]); - __count_vm_event(PGROTATED); + __count_vm_events(PGROTATED, nr_pages); }

if (active) - __count_vm_event(PGDEACTIVATE); + __count_vm_events(PGDEACTIVATE, nr_pages); update_page_reclaim_stat(lruvec, file, 0); }

@@ -870,6 +871,7 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec, { enum lru_list lru; int was_unevictable = TestClearPageUnevictable(page); + int nr_pages = hpage_nr_pages(page);

VM_BUG_ON_PAGE(PageLRU(page), page);

@@ -907,13 +909,13 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec, update_page_reclaim_stat(lruvec, page_is_file_cache(page), PageActive(page)); if (was_unevictable) - count_vm_event(UNEVICTABLE_PGRESCUED); + __count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages); } else { lru = LRU_UNEVICTABLE; ClearPageActive(page); SetPageUnevictable(page); if (!was_unevictable) - count_vm_event(UNEVICTABLE_PGCULLED); + __count_vm_events(UNEVICTABLE_PGCULLED, nr_pages); }

add_page_to_lru_list(page, lruvec, lru);